In the aforementioned valve opening and closing timing control apparatus, an accommodation portion for accommodating the torsion coil spring is provided at a radially inner side of the driven-side rotational member. In a case where a relative rotational phase between the drive-side rotational member and the driven-side rotational member changes, a degree of torsion of the torsion coil spring changes within the accommodation portion, which changes outer diameter dimensions of the torsion coil spring. With the aforementioned configuration change, a portion of the torsion coil spring may slidably move relative to a bottom surface or an inner wall surface of the accommodation portion. In this case, an abrasion of a portion of the driven-side rotational member relative to which the coil spring slidably moves becomes a problem.
In order to address the aforementioned abrasion, according to a valve opening and closing timing control apparatus disclosed in Patent document 1, for example, a flower-shaped oil reservoir portion is provided at a contact surface of a driven-side rotational member making contact with a torsion coil spring so as to enhance a lubrication performance of the torsion coil spring. At this time, because oil includes foreign substances such as abrasion powders, for example, plural drain hole portions are provided at the oil reservoir portion so as to penetrate through the driven-side rotational member in an axial direction thereof. The oil is easily discharged via the drain hole portions when the valve opening and closing timing control apparatus is stopped to thereby remove the foreign substances.
In a valve opening and closing timing control apparatus disclosed in Patent document 2, a washer is arranged between a driven-side rotational member and a torsion coil spring in a rotation axis direction of the driven-side rotational member. The washer includes a guide portion obtained by cutting and lifting-up an outer edge portion to support the torsion coil spring from an inner side and a washer portion arranged between a surface of the torsion coil spring extending in a radial direction thereof and the bottom surface of the accommodation portion of the driven-side rotational member. Deformation of the torsion coil spring in the radial direction is restrained by the guide portion to thereby inhibit a contact between an outer peripheral portion of the torsion coil spring and an inner peripheral surface of the accommodation portion. In addition, the washer portion inhibits a contact between the torsion coil spring and the bottom surface of the accommodation portion of the driven-side rotational member. Because the torsion coil spring and the driven-side rotational member are configured so as not to directly make contact with each other, an abrasion of the driven-side rotational member in association with changes in outer diameter dimensions of the torsion coil spring is restrained.